1. Reservation of Copyright
The disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent files or records, but otherwise reserves all copyrights whatsoever.
2. Field of Invention
The present invention relates to image processing, and, more particularly, to a method and apparatus for subsampling an image so that the subsampled image may be further processed within certain constraints.
3. Description of Background Information
In the field of image processing, whatever its ultimate application, the general conventional approach is that shown in FIG. 1, wherein first an image is obtained (at P10) and then the image is processed (at P12). Typically, the processing of the image becomes more accurate as the resolution of the image increases. That is to say, the greater the resolution of the image, the more accurate the result of the image processing. However, image processing time is almost always also a function of the resolution of the image, so that the greater the resolution (and therefore the accuracy), the greater the amount of time taken to process the image.
If image processing time is not an issue, the best possible accuracy can be achieved. However, in many applications, processing time and memory space constraints exist, and consequently accuracy must be sacrificed to operate, if possible, within these constraints.
In general, performing image processing (P12 in FIG. 1), using the entire input image may cause the processing to take too long and/or require the use of too much memory space. On the other hand, using too little of the input image may cause the result of subsequent image processing to not be sufficiently accurate.